Titration is a laboratory method used to determine the unknown concentration of an acid or base by reacting it with a solution of known concentration. Here’s how it works step by step:
- Setup:
- The solution of unknown concentration (acid or base) is measured and placed in a flask.
- A solution of known concentration (called the titrant) is placed in a burette, which allows precise measurement of volume.
- Reaction:
- The titrant is slowly added to the unknown solution.
- The acid and base react in a neutralization reaction (acid + base → salt + water).
- Indicator/Endpoint:
- An indicator (like phenolphthalein or methyl orange) is added to show when neutralization is complete.
- The endpoint is reached when the indicator changes color, meaning the acid and base have reacted in the correct ratio.
- Calculation:
- The volume of titrant used is measured.
- Using the known concentration and volume of the titrant, and the reaction ratio from the chemical equation, the unknown concentration of the acid or base is calculated.
In short: Titration determines the concentration of an acid or base by carefully adding a solution of known concentration until neutralization occurs, then using the volumes and reaction ratio to calculate the unknown concentration.